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Sample-based synthesis chip used in a bunch of Taito arcade machines and PC sound cards like Soundscape Elite. A variant of it was the heart of the well-known Gravis Ultrasound. It has a whopping 32 channels of 16-bit PCM and:
  • Real time digital filters
  • Linear interpolation
  • Loop start and stop positions for each voice (bidirectional and reverse looping)
  • Internal volume multiplication and stereo panning
  • Hardware support for short envelopes

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Effects

  • 11xx: Set filter mode. Values are 0 through 3.
  • 120x: Set pause (bit 0). Pauses the sample until the bit is unset; it will then resume where it left off.
  • 14xx: Set filter coefficient K1 low byte.
  • 15xx: Set filter coefficient K1 high byte.
  • 16xx: Set filter coefficient K2 low byte.
  • 17xx: Set filter coefficient K2 high byte.
  • 18xx: Set filter coefficient K1 slide up.
  • 19xx: Set filter coefficient K1 slide down.
  • 1Axx: Set filter coefficient K2 slide up.
  • 1Bxx: Set filter coefficient K2 slide down.
  • 20xx: Set envelope count.
  • 22xx: Set envelope left volume ramp.
  • 23xx: Set envelope right volume ramp.
  • 24xx: Set envelope filter coefficient K1 ramp.
  • 25xx: Set envelope filter coefficient K1 ramp (slower).
  • 26xx: Set envelope filter coefficient K2 ramp.
  • 27xx: Set envelope filter coefficient K2 ramp (slower).
  • 3xxx: Set coarse filter coefficient K1.
  • 4xxx: Set coarse filter coefficient K2.
  • 81xx: Set panning (left channel).
  • 82xx: Set panning (right channel).
  • 88xx: Set panning (rear channels).
  • 89xx: Set panning (rear left channel).
  • 8Axx: Set panning (rear right channel).
  • 9xxx: Set sample offset.
    • Resets sample position to xxx * 0x100.
  • DFxx: Set sample playback direction.

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Info

Sample memory is split into 2MB banks, making the maximum sample length 2097024 bytes.

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Chip Configuration

The following options are available in the Chip Manager window:
  • Output rate divider: Sets the number of channels used in mixing. Ranges from the value set in “Channels” below up to 32.
    • As the chip mixes more channels, its output sample rate goes down, which also affects filtering.
    • Higher output rates (lower dividers) consume significantly more CPU, so even when using fewer active channels, it’s best to keep this divider as high as possible. A /22 divider is sufficient for 44100 Hz output.
  • Volume scale: Allows you to lower the overall volume to prevent clipping/distortion when using too many channels.
  • Amiga channel volumes: Makes volume linear, from 0 to 64 (40 in hex). Used in S3M, XM and IT import.
  • Amiga-like pitch: Pretends to be an Amiga, with periodic slides. Used in S3M, XM and IT import (the latter two when linear slides are disabled).
    • Only effective when pitch linearity is None.
  • Channels: Sets the number of channels, from 5 to 32.

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